Let’s Get Technical…Thoracic Outlet Syndrome
Many say that a picture is worth a thousand words, well in this case the following description is worth 3 words; Thoracic Outlet Syndrome. Imagine being on an elevator all by yourself, then suddenly two or three rather large men squeeze their way in, on top of that you have groceries, a dog, 3 children, a handbag or briefcase, etc. and you are trying to keep from getting stepped on. By the time you reach the next floor there are so many people on the elevator that someone or something in your “bunch” gets squeezed so hard that it begins to suffocate, by this time, it’s a chain reaction, first the groceries fall, then the dog barks, and the children start crying, and now your headache is enough to make you just want to go numb! This is exactly what happens with Thoracic Outlet Syndrome, which is less formally known as TOS. This article will explain what actually happens to the certain areas of the body when someone has TOS. It will also explain the effect that the pectoralis minor has with this disorder.
The American Heritage Stedman’s Medical Dictionary defines thoracic outlet syndrome as compression of the brachial plexus and subclavian artery by attached muscles in the region of the first rib and the clavicle, characterized by pain in the arm, numbness in the fingers, and weakness in the hand muscles. As the above illustration states, the nerves and arteries are basically fighting for space and the end result is a tired upper extremity whose only relief is numbness and tingling. The thoracic outlet is actually located on the upper chest cage; its area is approximately four centimeters and is boundaried anteriorly by the manubrium of the sternum, laterally by the first rib and its adjacent costal cartilage, and posteriorly by the body of thoracic vertebrae 1. The scalene muscles, work to pull the ribs upward in a superior direction while the pectoralis minor pulls the scapula inferior, which narrows the space between the clavicle and the ribs. These closely structured bones, strong muscles and all other superficial structures in this area are the most common reasons why impingement or compression on the neurovascular bundle is so common.
The pectoralis minor plays an important role because it assists with making the space (thoracic outlet) smaller. The functions of the pectoralis minor include, shoulder depression, protraction, downward rotation of the scapula, and finally elevation of the ribs in forced inspiration. Now, when we consider that one of the main reasons for TOS is a narrowed space, we can see how the pectoralis minor plays a role in this. The pectoralis minor depresses the shoulder girdle, when this happens it entraps the axillary nerves, brachial plexus, and subclavian vein between the pectoralis minor tendon and the ribs, thus leading to the symptoms described above.
People with drooping shoulders, abnormalities of the muscles in the neck or of the first rib, or prior injuries to the muscles or bones in this particular area have an increased chance of developing TOS. Studies have shown that TOS may be associated with certain occupations that involve working in a static position for prolonged periods of time as well as jobs involving heavy lifting.
The main objective of treatment includes relieving the compression of the nerves and blood vessels in the thoracic outlet region; controlling and minimizing pain and other symptoms to the greatest extent possible; and improving the patient’s overall quality of life.
In conclusion, our posture, genetic predisposition, and daily activities play an important role in the development of thoracic outlet syndrome. This seldom researched yet growingly common disorder has many doctors and other health care providers’ thinking that surgery is the only option for suffers. With special care many massage and neuromuscular body workers are learning how to better assist clients that have been diagnosed with TOS.
At times is difficult to avoid overcrowding on an elevator or subway car, the beauty of the human form is that you can adjust yourself for comfort. Your body isn’t so lucky, it will continue making adjustment for your comfort until one day your muscles decide to go on “strike”. Prevention is key.